Starting device for internal-combustion engines



Mai. 6, 1923. 7 1,447,464

E. FRIEDRICHS STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Aug. 11, 1921 Patented MarQfi, 1923.v

UNITED STATES 1,447,464 PATENT OFFICE.

ERNST FRIEDRICHS, OI STU TTGART, GERMANY, ASSIGNOR TO THE FIRM: ROBERT BOSCH AKTIENGESELLSG'HAFT, OF STUTTGART, GERMANY.

STARTING DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Application filed August 11, 1921. Serial No. 491,569.

To all whom it may concern: I

Be it known that ERNST FRIEDRIoHs, a subject of Germany, residin at and whose post-ofiice address is Eduard feiifer-Strasse 117, Stuttgart, Germany, has invented certain new and .useful Improved Starting Devices for-Internal-Combustion Engines, for

whichI- have filed applications in Germany,

Sept. 22, 1919; Austria, Aug. 26, 1920 Switzerland, Aug. 26, 1920; Sweden, Aug. 27 1920; Czechoslovakia, Sept. 9, 1920; Italy, Sept. 1591920; Netherlands, Sept. 16, 1920; Belgium, Sept. 16, 1920; France, Sept. 20, 1920; and Great Britain, Sept; 22, 1920, and

- of which the following is a specification. '.Thisinvention relates to electromotoric.

startingdevices of the kind described and shown in the pending UnitedStates'application Serial Number 318,808, filed August 20, 1919, patented May 2, 1922, Patent Not 1,414,653, and intended for use in connection with internal combustion engines. Such startingdevices are, as a rule, coupled with the ing to the starting-device described and.

1 shown insaid pending application, the resistance, with aid of which thedlflerentiated manner ofoperation is obtained, forms a 40 portion of the exciting coil of the startlng motor. I

- As withother starting devices, where, for

instance, in the first stage a shunt is laid around the armature of the' starting motor and'a special series resistance is provided,

so also the novel arrangement allows of letting switching from the first stage to the secondproceed automatically; vi z.,; with aid of. an electromagnetic switch which is actuated by the coupling motion of the coupling mem ber of the starting'motor.

, Now, the present lnvention consists firstly, in making the excitation of this electromagnetic switch controlled solely by the starting switch (pushbutton) so that the switch is with the associate coupling member traversed by the weaker current of the first stage hereinbefore referred to; secondly, in preventing by suitable means the switch from effecting the switching from the first stage to the second before the pinion of the starting motor has meshed with the toothed fly-wheel rim of the internal combustion engine. The desired dependency of the switch in question upon ,the starting switch is obtained, for instance, by laying the coil of the former switch directly in the circuit of the starting motor. P

Compared with starting devices with electromagnetic switch traversed by current only. after the pinion has been shoved into coupling position, the novel device offers the great advantage that no special safety means preventing a spontaneous repetition of the starting procedure after the starting of the internal combustion engine are required, such repetition being prevented by the starting device itself.

An especially simple and reliably operating form of construction of the invention consists in mechanically locking the arma ture of the electromagnetic switch, that looking being directly or indirectly released by the pinion only after a certain distinct displacement of this latter.

In order to make my invention more clear, I refer to the accompanying drawing, in

which a combination and, arrangement of x parts embodying it is diagrammatically illustrated. v v

The shaft 6 of the armature 1" has aflixedv toit a pinion a. ,The shaft with the armature may ,be longitudinally displaced in its bearings. A spring p is provided between one of the bearings and the armature and displaces this latter, in its position. of rest, in sucha direction as to position the pinion a outof mesh with the toothed rim 0 of the fly wheel of the internal combustionengine. e is a hand-operated switch, preferably a push-button. By closin it, current flows from the battery. 01 over t e brush through the armature 1", over the brush lc fthrough the portion 9 of the exciting windingof the startingmotor and the winding 0 of. the electromagnetic switch S, over the handswitch e and the earth back to the battery d. The: armature is now attracted and drawn into the exciting field arid is ,at the same time slowly turned because the portion g of the exciting winding which has a high resistance prising,

' exciting field,.a disk n aiiixed to the rear end also through. the main exciting winding f.

lies in series with the armature 'winding.

Owing to this manner of operation the pinion a meshes easily and free of jerks wlth the toothed rim 0. p

Simultaneously with the field winding 9 the winding o-of the switch S has also'been excited, it is" true, but for the present, the switch cannot attract its armature m because this is prevented from any alterationof its,

position by a pawl h. x i

As soon, however, as the motor armature has been drawn for a certain length lnto the of the armature shaft 6 pushes against the pawl h and alters, while ,the longitudinal motion of thearmature proceeds, its position in such a manner that the switch armature is released and is now able to follbw the magnetic attraction of thewinding 0. Owing to this motion, the switch connects .the contacts 2' and 2' with each other andthe battery current flows now from the brush 7c,

and over said contacts to the earth. But as the resistance of the winding f is considerably lesser than the resistance of the winding 9, the motor armature, owing to the two portions f and g of the exciting winding having been connected in parallel, is fed with a strong current so that it exerts a powerful turning moment upon the flywheel ofthe internal combustion engine, the

toothed-fiy-wheel rim of which is, now in complete mesh with the pinion a.

Although the motor armature mayaxially sway while the hand switch is closed, still, the starting procedure cannot spontaneously repeat because the winding 0' of the switch 3.,- owing to its being located in the circuit of the starting motor, remains excited only as long as the hand switch is closed, and the motor armature r, during-its return motion,

coupling member 1 in driving engagement with the internal combustion engine; a startmg swltch; an electromagnetic, switch, the

1 excitation of which is controlled solely by said starting switch; -a mechanical locking device adapted to prevent the armature of the said "electromagnetic,switch from edect ing the switching fromthe'first stage to the second before said' two coupling members have engaged each other, and mechani c'al means for releasing said locking device, said lease the pawl, 's'ubst means being adapted to be actuated by the longitudinal motion of the motor armature shaft. I I

2. A two stage electromagnetic starting device for internal combustion engines, com-' pnising, in combination: an electromotor having )3, longitudinally displaceable arma-' ture' and armature shaft; a coupling memher at the shaft end and a complementary coupling member in driving engagement with the internal combustio engine; a first tor; a starting switch; an electromagnetic switch having its winding in series with the first stage field winding of said motor for cutting in the second stage field winding; and means adapted to prevent said electromagnetic switch from effecting the switching from the first stage to the second before said two coupling members have enaged each other.

and second stage; field winding for theino 3. A two stage electromagnetic starting I ture and armature shaft; a coupling memher at the shaft end and a complementary coupling member in. driving engagement device for internal combustion engines, comprising, 1n comblnationz' an electro'motor having a,long1tuol 1nally dlsplaceable armawith the internal combustion engine; a starting switch; an electromagnetic switch, the

said starting switch and which has a solenoid core forming the movable member;

' excitation of which is controlled solely by a pawl adapted to lock said core in its outer position; a contact-closing meansconnected with the Qcore; and means affixed to the motor armature shaft and adapted to reantia lly and for the purpose as described.

A two stage electromagnetic starting device for internal combustion engines, comprising, in combination an electromotor having a longitudinally displaceable armature and armaturesh aft; a coupling mem-' be r at the. shaft end and a complementary coupling member for the internal combusftion engine; a starting switch; an electromagnetic switch, the excitation of which is controlled solely by said starting switch; a mechanical locking device adapted to prevent the armature of thesaid electromagnetic switch from effecting the switching from the first stage to the second before said two coupling members have engaged each other, and mwha-nical means for releasing said locking device,- said means being adaptedto be actuated by the longitudinal motion of the motor armature shaft. a 5. A! two. stage electromagnetic starting device for internal combustion engines, comprising, in combination: an electromotor having a longitudinally displaceable armature and'armature shaft; a coupling member at the shaft end and a complementary coupling member. for the internal combustion engine; a starting .switch; an electromagnetic switch, the excitation of which is controlled solely by said starting switch; a solenoid core forming the .moveable member of said electromagnetic switch; a pawl adapted to lock said core in its outer position; a contact-closing means connected with the core; and means afiixed to the motor armature shaft and adapted to release the pawl, substantially and for the purpose as described.

(3. A two stage electromagneticstarting device for internal combustion engines comprising in combination an electric motor having a longitudinal displaceable armature shaft; a coupling member at the shaft end. a complementary coupling member for the engine, first and second stage field windings for the motor, a starting switch controlling the circuit of said first stage windin" an electromagnetic switch energized in n s the circult of said first stage winding, and

interlocking means permitting a closing movement of said electromagnetic switch only during engagement of the coupling members while permitting opening movement of the said switch at all times.

7. In a two stage starting device of the type described. the combination. with the starting motor and complementary clutch members. of an electromagnetic switch for the motor. means for energizing the same and interlocking means between said switch and clutch member permitting a closing movement of the switch only during engagement of the clutch members while permitting opening movement of the switch at all times. i

In testimony whereof I aflix my signature in presence of two witnesses.

ERNST FRIEDRICHS.

Witnesses:

ALFRED Moznn. HELMA PANDER. 

